Precisely this toxic person is a bully and has been derailing and causing problems on the Forum for a long time. I don’t know why admins tolerate his antics (corrected based upon popular request) everyday. I can understand the practical limitations but I don’t understand why this person is not being reprimanded? Is it just because he engages in micro aggressions, which cannot be classified as excessive at once? Then the admins should look at the bigger picture. He is the reason why many hesitate to post and comment because he lacks civility and attacks the person under the garb of pigeon holing and what not like a third rate debater. The forum becomes less engaging because of such persons. Such people are hindering full participation on the forum.
This is a bad human problem, technology can provide solution but as you listed out the limitations, it seems neither Xenforo nor Discourse enable this. Admins should be able to take active steps to reprimand these uncivil toxic bullies. I have seen this persons posts getting deleted or edited by moderators left and right for being rude and off topic, too frequently for a normal person. All these indicating that this person is not here to engage in healthy discussion but he is here for the cathartic experience of harassing someone while edging on the rules of this forum. @admins should do something about such terrible people on the forum.
After I made this post, I have been approached by a few people regarding the toxic behaviour of certain members resulting in bullying and subsequently reduction in their participation on the forum.
These toxic people who vitiate the healthy discursive environment of the forum must be held to account.